BoilerFaultCodesTechnical description
condensate pump or feedback of accessorie blocks heating | condensate pump defective or flume flap feedback triggered
What causes this fault?
This fault occurs when the boiler's internal safety system detects that waste water cannot properly exit the unit, or a mechanical flap in the flue pipe has failed to open. The most common cause is a blockage or electrical failure in an external condensate pump that is responsible for carrying away excess liquid. It can also be triggered if the flue system is obstructed, preventing the boiler from safely exhausting its gases.
This fault is frequently seen during freezing winter spells, as the external drain pipes can freeze solid, causing water to back up into the pump or boiler.
Engineer required
This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.